Actively steerable guidewire

Abstract

A steerable elongate medical device includes a composite shaft and a handle that is removably securable to the composite shaft. The composite shaft includes a first shaft component and a second shaft component. The composite shaft bends in a first direction when the first shaft component is heated above a transition temperature and bends in the first direction. The composite shaft bends in an opposing second direction when the second shaft component is heated above the transition temperature and bends in the second direction. The handle enables a user to selectively pass an electrical current through either of the first shaft component or the shaft component in order to electrically heat the selected shaft component.

What is claimed is: 
     
         1 . A steerable elongate medical device, comprising:
 a composite shaft extending from a proximal region to a distal region, the distal region adapted to selectively bend in a first direction or an opposing second direction, the composite shaft including:
 a first shaft component having a straight configuration below a transition temperature and a curved configuration above the transition temperature, the first shaft component causing the composite shaft to bend in the first direction when the first shaft component is in its curved configuration; 
 a second shaft component having a straight configuration below the transition temperature and a curved configuration when above the transition temperature, the second shaft component causing the composite shaft to bend in the second direction when the second shaft component is in its curved configuration; and 
 an intervening member separating the first shaft component and the second shaft component; and 
   a handle removably secured to the proximal region, the handle including:
 a housing adapted to be removably secured to the proximal region of the composite shaft; and 
 a knob rotatably secured relative to the housing, the knob including:
 a knob body; 
 a first electrical contact disposed on the knob body and adapted to contact the first shaft component when the knob is rotated to a first position; and 
 a second electrical contact disposed on the knob body and adapted to contact the second shaft component when the knob is rotated to a second position. 
 
   
     
     
         2 . The steerable elongate medical device of  claim 1 , wherein:
 the first shaft component is adapted to increase in temperature when an electrical current passes through the first shaft component; and   the second shaft component is adapted to increase in temperature when an electrical current passes through the second shaft component.   
     
     
         3 . The steerable elongate medical device of  claim 1 , wherein the first shaft component and the second shaft component each comprise a shape memory metal. 
     
     
         4 . The steerable elongate medical device of  claim 1 , wherein the first shaft component and the second shaft component each comprise nitinol. 
     
     
         5 . The steerable elongate medical device of  claim 2 , wherein:
 the first electrical contact is adapted to make electrical contact with the first shaft component when the knob is rotated to the first position; and   the second electrical contact is adapted to make electrical contact with the second shaft component when the knob is rotated to the second position.   
     
     
         6 . The steerable elongate medical device of  claim 1 , wherein the knob is adapted to be rotated to a neutral position in between the first position and the second position in which neither of the first electrical contact or the second electrical contact make electrical contact with either the first shaft component or the second shaft component. 
     
     
         7 . The steerable elongate medical device of  claim 2 , wherein the knob further comprises a power connector that is electrically coupled with the first electrical contact and the second electrical contact. 
     
     
         8 . The steerable elongate medical device of  claim 2 , further comprising a conductive member in electrical contact with a distal region of the first shaft component and a distal region of the second shaft component in order to complete a circuit. 
     
     
         9 . The steerable elongate medical device of  claim 1 , wherein the transition temperature is above 37° C. 
     
     
         10 . The steerable elongate medical device of  claim 1 , wherein the intervening member comprises an insulating member. 
     
     
         11 . The steerable elongate medical device of  claim 1 , wherein the intervening member comprises a thermoelectric circuit adapted to selectively heat one of the first shaft component and the second shaft component. 
     
     
         12 . The steerable elongate medical device of  claim 1 , wherein the first shaft component includes a plurality of cuts formed within the first shaft component in order to enhance articulation of the first shaft component. 
     
     
         13 . The steerable elongate medical device of  claim 1 , wherein the second shaft component includes a plurality of cuts formed within the second shaft component in order to enhance articulation of the second shaft component. 
     
     
         14 . A steerable guidewire, comprising:
 a composite shaft adapted to selectively bend in a first direction or an opposing second direction, the composite shaft including:
 a first shaft component movable between a first configuration and a second configuration, the first shaft component adapted to move into the second configuration when electrically heated; and 
 a second shaft component movable between a first configuration and a second configuration, the second shaft component adapted to move into the second configuration when electrically heated; and 
   a handle adapted to be removably secured to the composite shaft, the handle selectable between:
 a first position in which an electrical current is provided to the first shaft component; 
 a second position in which an electrical current is provided to the second shaft component; and 
 a third position in which no electrical current is provided. 
   
     
     
         15 . The steerable guidewire of  claim 14 , wherein the first shaft component and the second shaft component each comprise a shape memory metal. 
     
     
         16 . The steerable guidewire of  claim 14 , wherein the first shaft component and the second shaft component each comprise nitinol. 
     
     
         17 . The steerable guidewire of  claim 14 , wherein the first configuration of the first shaft component and the first configuration of the second shaft component each correspond to a straight configuration of the composite shaft. 
     
     
         18 . The steerable guidewire of  claim 14 , wherein:
 the first shaft component causes the composite shaft to bend in the first direction when the first shaft component is electrically heated and the second shaft component is not electrically heated; and   the second shaft component causes the composite shaft to bend in the second direction when the second direction is electrically heated and the first shaft component is not electrically heated.   
     
     
         19 . The steerable guidewire of  claim 14 , wherein the composite shaft has a neutral configuration when neither the first shaft component nor the second shaft component are electrically heated. 
     
     
         20 . A steerable guidewire, comprising:
 a composite shaft adapted to selectively bend in a first direction or an opposing second direction, the composite shaft including:
 a first shaft component movable between a neutral configuration and a curved configuration, the first shaft component adapted to move into the curved configuration when electrically heated, the first shaft component comprising nitinol; and 
 a second shaft component movable between a neutral configuration and a curved configuration, the second shaft component adapted to move into the curved configuration when electrically heated, the second shaft component comprising nitinol; 
   wherein the composite shaft is adapted to bend in the first direction when the first shaft component is in its curved configuration and the second shaft component is in its neutral configuration;   wherein the composite shaft is adapted to bend in the opposing second direction when the first shaft component is in its neutral configuration and the second shaft component is in its curved configuration; and   wherein the composite shaft is adapted to remain in a neutral configuration when the first shaft component is in its neutral configuration and the second shaft component is in its neutral configuration.